// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
  install(Vue, options) {
    Vue.prototype.getPdf = function() {
      window.pageYoffset = 0
      document.documentElement.scrollTop = 0
      document.body.scrollTop = 0
      var title = this.htmlTitle
      let pdfDom = document.querySelector('#pdfDom')
      html2Canvas(pdfDom, {
        scale: 1,
        width: pdfDom.clientWidth,
        height: pdfDom.clientHeight,
        scrollY: 0,
        scrollX: 0,
        useCORS: true // 【重要】开启跨域配置
      }).then(function(canvas) {
        let contentWidth = canvas.width
        let contentHeight = canvas.height
        let pageHeight = (contentWidth / 595) * 842
        let leftHeight = contentHeight
        let position = 0
        let imgWidth = 595
        let imgHeight = (595 * contentHeight) / contentWidth
        let pageData = canvas.toDataURL('image/jpeg', 1.0)
        let PDF = new JsPDF('', 'pt', 'a4')
        if (leftHeight < pageHeight) {
          PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
        } else {
          while (leftHeight > 0) {
            PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
            leftHeight -= pageHeight
            position -= 842
            if (leftHeight > 0) {
              PDF.addPage()
            }
          }
        }
        PDF.save(title + '.pdf')
      })
    }
  }
}
